偶联剂KH和聚合物PVA在硫铝酸盐─MDF水泥中的作用机理

以硫铝酸盐水泥为基材，采用有机聚合物ＰＶＡ，并且在ＭＤＦ（Ｍａｃｒｏ—Ｄｅｆｅｃｔ—Ｆｒｅｅ）水泥中添加偶联剂ＫＨ，制备出抗折强度大于１７０ＭＰａ，抗压强度达２４０ＭＰａ的新型ＭＤＦ水泥、同时，借助于Ｘ射线光电子能谱分析（ＸＰＳ），红外光谱分析（ＩＲ）等测试手段研究了偶联剂ＫＨ和聚合物ＰＶＡ在硫铝酸盐－ＭＤＦ水泥中的作用机理

ACTION MECHANISM OF COUPLING AGENT ANDPOLYMER IN SULPHOALUMINATE-MDF CEMENT

A new type of sulphoaluminatae-MDF cement with the long-term stability and larger bending strength is going to be prepard. The chemical action mechanism of KH and PVA in this cement is investigatd.Three samples about C4A3S, KC and PC are analysed by means of XPS, IR and XRD. The experimentalrsults show that there exist coupling raction, chemical binding action between KH and C4A3S and the chemical reaction between PVA and hydration products of C4A3S. The polar functional group hydroxyl-OH oforganic polymer PVA and cement hydration products as well as unhydrated cement particles' surfaces canproduce binding function and form chemical bonds. Which benefits the enhancement of the strength andtoughness of MDF cement. The coupling agent KH possessing organophilic and inorganophilic chemicalfunctional groups not only produces coupling raction with cement particles, but also producesphysiochemical action with organic polymer PVA by the aid of disprsion force and hydfgen bonds so that thestrength, toughness and chemical stability of MDF cement can be further improved. A new type of MDF ce-'ment with the bending strength larger than 170 MPa and compressive strength equal to 240 MPa issuccessfuly prepard.